Study on dynamic response of rock foundation pit blasting excavation to adjacent buildings

Abstract

Focusing on safety problems of the blasting excavation of foundation pits near existing buildings, this study takes the Jinggangshan Road Station of Qingdao Metro Line 1 as the engineering background and establishes a three-dimensional numerical model of a foundation pit blasting excavation based on the dynamic response characteristics of buildings using the FLAC3D finite difference software. Moreover, the present study examines the dynamic response law of foundation pit blasting excavations under blasting vibrations and analyzes blasting vibration velocities at different measuring points near buildings. Results show that the blasting vibration velocity of key measuring points is consistent with the numerical simulation results. This finding demonstrates that the numerical model is reasonable; the influence of blasting vibrations on buildings presents different trends with varying heights, mainly concentrated in the lower part of the blasting side; the vibration velocity of the measuring points of buildings varies with different horizontal distances; and the impact of the monitoring points near the blasting side is far greater than that of the measuring points far from the blasting side. Velocity decreases as the distance between the detonation centers increases. The results have certain reference value and guiding significance in the selection of reasonable blasting parameters and the effective improvement of the safety threshold of foundation pit blasting vibrations.